U.S. patent number 3,625,517 [Application Number 04/875,454] was granted by the patent office on 1971-12-07 for golf putter with center of mass aligned with shaft axis.
Invention is credited to John E. Durnack.
United States Patent |
3,625,517 |
Durnack |
December 7, 1971 |
GOLF PUTTER WITH CENTER OF MASS ALIGNED WITH SHAFT AXIS
Abstract
A golf club which includes a shaft having an upper end with a
gripping surface and a lower end adapted to be mounted to the shank
portion of a head. The head has the shank portion extending
upwardly from its upper surface intermediate the ends thereof. The
head also has a striking face thereon and an arcuate recess on its
undersurface along with an upward projection extending from its
upper surface. The recess and the projection are proximal to the
substantially vertical axis and the extension thereof of the shank
part of the head.
Inventors: |
Durnack; John E. (Hollis,
NY) |
Family
ID: |
25365838 |
Appl.
No.: |
04/875,454 |
Filed: |
November 10, 1969 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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712849 |
Mar 13, 1968 |
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Current U.S.
Class: |
473/313;
473/340 |
Current CPC
Class: |
A63B
53/0487 (20130101); A63B 53/007 (20130101); A63B
53/0433 (20200801) |
Current International
Class: |
A63B
53/00 (20060101); A63b 053/04 () |
Field of
Search: |
;273/8C,167-175,77R
;D34/5 (9)/ |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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7,550 |
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1900 |
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GB |
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340,579 |
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Jan 1931 |
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GB |
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Primary Examiner: Oechsle; Anton O.
Assistant Examiner: Apley; Richard J.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of my previously filed
application, Ser. No. 712,849 filed on March 13, 1968, and now
abandoned and incorporates by reference all of the subject matter
of that previously filed application.
Claims
I claim:
1. An elongated blade putter comprising: a shaft having an upper
end with a gripping surface thereon and a lower end, a head having
a shank portion extending upwardly therefrom intermediate the ends
thereof and having a striking face thereon, the shank portion
adapted to be mounted to the lower end of said shaft to thereby
form the golf club, the head having an arcuate recess on its
undersurface and an upward projection disposed intermediate the
heel of the club head and approximate center of the club head
extending from the upper surface thereof, said recess and said
projection being aligned with the shaft axis and the extension
thereof of the shank portion of the head, the arcuate recess formed
intermediate the ends of the head and along the longitudinal axis
of the blade extending across the entire cross section undersurface
of the head, each end of the recessed arcuate undersurface of the
head terminating in a contact point for the head with the ground,
the undersurface then continuing in a curved configuration away
from the ground to assist in forming curved end portions on said
head so that when the putter is in the hitting position the
undersurface of its head will only contact the ground at two points
determined by the small portions of the undersurface of the head
adjacent to the recessed portion thereof, the striking area of the
head being aligned with the shaft axis and the extension thereof of
the shank thereby minimizing the torque effect when a ball is
struck and alleviating the danger of turning of the club head
during the stroke causing subsequent misdirected hitting of the
ball, and the distribution of the weight of the projection and the
recess aligned substantially with the shaft axis and the extension
thereof of the shank in substantial alignment locating the center
of mass of the head with respect to the ground at a position above
the geometric horizontal axis of the head so that the striking
point of the head with a ball upon proper contact at the point of
the center of mass of the head will be on the upper portion of the
ball and will consequently impart top spin to the ball subsequent
to the striking thereof.
Description
BACKGROUND OF THE INVENTION
In the game of golf when the ball is lying on the green or in
slightly taller grass in the fringe surrounding the green and it
must be struck with a putter in order to properly advance it toward
the hole, there are several deleterious effects which may occur due
to the structure of the putter itself which consequently may cause
an undesirable result. For example, if the undersurface of the
putter strikes the ground prior to contact with the ball, commonly
known as stubbing the grass before making contact with the ball,
the ball will be improperly struck and will not roll smoothly in
the direction of the hole.
In the putters commonly utilized today, the contacting surface of
the underside of the putters extend virtually the entire length of
the undersurface thereof so that contact with the ground may occur
at any point along the undersurface of the putter. Therefore, if
there is a slight bump or projection extending upward from the
ground at any point on the ground within the length of the putter,
stubbing may occur. Furthermore, should the golfer himself execute
an incorrect stroke so that the blade does contact the ground prior
to hitting the ball due to his particular stroke of the putter,
there will be contact between the entire undersurface of the putter
and the ground which would create a strong stubbing force.
Therefore, it would be extremely advantageous in the art, if a
putter could be provided where there is only minimum contact
between the undersurface of the head of the putter and the ground
at any time either prior, during or after the stroke.
A second problem which is quite prevalent with putters in use today
is the presence of a torsion effect which occurs when the ball is
struck by a portion of the putter remote from the axis of the
center of mass of the club. For example, the weight is commonly
distributed uniformly across the blade of the putter so that the
majority of weight is not concentrated adjacent the vertical axis
of the shaft or the extension of that axis down through a portion
of the head of the club. In such an instrument, if the ball is
struck with a remote tip of the head of the putter, the force at
that point in conjunction with the weight of the putter will result
in a turning or torque action of the putter head and consequent
rotation of the club in the golfer's hand if the club is not held
tightly enough which could cause the ball to be struck at an
undesired angle and consequent directing of the ball in an
undesired line of travel. In order to overcome this problem, the
golfer often grips the club too tightly so that he loses the feel
of contact between the club head and the ball and the force of
contact directed from the club head to the ball cannot be easily
gauged correctly. Furthermore, if he grips the club in a loose
manner, in order to take advantage of the feel and impart the
proper force to the ball depending upon the distance of the ball
from the hole, and the ball is not struck at the center of mass of
the club head, the developed torque will turn the shaft in the
golfer's hands as the club head turns with the result that the
completion of the stroke results in the ball being directed in an
incorrect direction of travel.
In the golfing world, it is also well known that a golf ball with
overspin coming in contact with the hole will have a tendency to
enter the hole if it comes in contact with any portion of the rim
of the hole. It is also well known that overspin is imparted to a
golf ball if it is struck above the horizontal centerline of the
ball so that it is desirable for the golfer to make contact with
the golf ball above the centerline of the ball to impart overspin
to the ball. Therefore, it would be advantageous to employ a head
on the putter which contains a striking point, or is commonly known
in the golfing world as the "sweet spot" on the head of the putter,
where proper contact with the golf ball may be encountered so that
it achieves the desired direction of travel. This "sweet spot" or
point of contact should be as near as possible to the center of
mass to the putter to minimize the torque effect as discussed above
and should also be a sufficient distance above the ground so that
it may contact the golf ball on its upper half and impart an
overspin to the golf ball to thereby achieve the desired effect on
the ball as it rolls toward the hole and comes in contact
therewith.
An additional advantage of having the "sweet spot" or point of
contact as high as possible on the hitting face of the head of the
putter comes into play when the ball is resting in the fringe on
the edge of the green adjacent to the closely cut green surface.
When the ball is in this position, it is resting in somewhat taller
grass and is often somewhat elevated from the ground. By having the
point of contact on the head of the putter as high as possible when
the putter rests down in the grass there is less danger of hitting
beneath the ball which results in an improper hitting effect and
path of travel of the ball.
Furthermore, by having minimum contact between the undersurface of
the putter head and the ground when it is resting in the fringe,
the danger of stubbing the putter in the tall grass is also greatly
minimized. It is readily apparent that this problem is even more
prevalent when the ball is in the fringe than when it is on the
green.
Consequently, by having a center of mass or hitting point on the
putter head which is at a maximum distance from ground level and
having minimum contact between the undersurface of the putter blade
and the ground, the above physical problems existent in the putting
stroke are at least alleviated if not completely eliminated.
Additionally, by concentrating the center of mass about the
vertical axis of the shank and the extension of that axis, the
above discussed danger of excessive torque during the hitting
action would also be alleviated.
Therefore, a putter which is structurally designed to take
advantage of the above discussed advantageous features would be
extremely helpful to the golfer in assuring that he properly
strikes the golf ball when it is resting on the green or in the
adjacent fringe area.
SUMMARY OF THE INVENTION
With the above discussion in mind, it is among the primary
objectives of this invention to provide a golf club in the form of
a putter which is constructed to minimize the danger of excessive
contact between the undersurface of the putter head and the ground
during the putting stroke, minimize the danger of excessive torque
being imparted to the putter during the putting stroke to cause
turning of the club in the hands resulting in a misdirection of the
ball subsequent to the putting stroke, and to provide an optimum
hitting point on the putter head which assists in imparting
overspin to the golf ball when it is struck and facilitates the
proper contact between the putter and the golf ball when the ball
is resting in the fringe adjacent to the green. Furthermore, the
putter of this invention is constructed so as to provide a greater
substantially torque-free hitting area on the putter head so that
the ball may be struck on any point within this area on the head of
the putter without imparting an excessive torque to the club which
could result in the deleterious aftereffects discussed above.
Furthermore, a putter is provided which has identical opposing
faces on the putter head so that it may be used as both a right
handed and left handed golf club.
In summary, a golf club is provided which includes a shaft having
an upper end with a gripping surface thereon and a lower end. A
head which has a shank portion extending upwardly therefrom
intermediate its ends is adapted to be connected to the lower end
of the shaft to form the resultant golf club. Additionally, the
head has a striking face thereon. An arcuate recess is present on
the undersurface of the head and an upward projection extends from
the upper surface of the head. The recess and the projection are
proximal to the vertical axis and the extension of that axis of the
shank portion of the head.
With the above objects, among others, attention is directed to the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a side elevation view of a putter embodying the
invention;
FIG. 2 is a sectional top view thereof taken along the plane of
line 2--2 of FIG. 1; and
FIG. 3 is an end elevation view thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1-3 of the drawings disclose a golf club which embodies the
general principles of the invention. As shown, the club includes a
shaft 21 with a gripping surface on its upper end (not shown) and
its lower end connected to the shank portion 22 of the head 23. A
shank 22, as shown, may be constructed integrally with the
remainder of head portion 23 and extends upwardly therefrom. Shank
22 may be connected to the lower end of shaft 21 in any convenient
manner such as by means of sleeve 24 having a recess therein to
receive shaft 21 in tight frictional engagement therewith. Once the
connection has been made, the golf club is completely assembled and
ready for use.
The angle at which shank 22 and shaft 21 in alignment therewith
extend upward from the remainder of head 23 is a matter of choice.
This depends upon the desire of the individual golfer in regard to
how he likes the putter positioned with respect to his feet and the
angle at which he wants the shaft to extend from head 23 into his
hands. In fact, shaft 21 need not extend its entire length in axial
alignment with shank 22 but may be bent with respect thereto with
the configuration once again being dependent upon the desire of the
particular golfer who is going to use the putter 20.
The remainder of head 23 other than shank 22 has the general
configuration of a foot which facilitates the desirable features of
its construction. Head 23 contains two hitting surfaces 25 and 26
on opposed sides of head 23 and of substantially the same
configuration. Both surfaces 25 and 26 will work equally well as
hitting faces for the putter and therefore the club 20 may be used
as either a right-handed or left-handed club.
As previously stated, the bottom portion of head 23 resembles a
foot in shape and this is facilitated by providing a recess 27 on
its undersurface intermediate the ends of head 23. Recess 27 is
located proximal to and substantially in alignment with the
extension of the vertical axis of shank 22 as shown. Complementary
to recess 27 is a projection 28 extending from the upper surface of
head 23 and terminating in shank 22 in the upward direction.
Consequently, the removal of material from head 23 in forming
recess 27 is complemented by an increase in material to form upward
extension or projection 28 on head 23. It will be noted from the
drawings that preferably at least one half of the material forming
head 23 is concentrated in the portion 29 of head 23 which is
proximal to the vertical axis of shank 22 and the extension in the
downward direction of that axis. By concentrating the majority of
the material of head 23 in this area, the torque effect on the club
during the hitting action is minimized as will be discussed in
detail below.
It can also be seen in FIG. 1 how the most desirable hitting point
on the hitting face or surface of head 23 is located in general
alignment with the vertical axis of shank 22 and is represented by
the most desirable hitting point on the putter or what is commonly
known as the "sweet spot" 30. This point 30 is the ideal position
on the club face with which to contact the ball during the putting
stroke to obtain the most desirable effects in rotation and path of
travel of the ball subsequent to the putting stroke.
When putter 20 is grounded behind the ball prior to the putting
stroke, only two relatively small portions 31 and 32 of the
undersurface of the putter head 23 come in contact with the ground.
These points 31 and 32 are located at the terminal ends of recess
27 and represent the apexes of a curvilinear surface on the
undersurface of head 23 which then extends in an arcuate
configuration toward the extremities of the head in an upward
direction to form curved end portions 33 and 34 which as shown do
not contact the ground during the putting stroke. It will also be
noted that one end portion 33 is considerably greater in length
than the other end portion 34. The reason for this particular
feature is manifold and one particular advantage will be discussed
in detail below.
The particular structural features of the head portion as outlined
above have considerable advantages when the putter is actually
utilized during the putting stroke. For example, with the majority
of the material massed adjacent to the vertical axis of shank 22,
the majority of the weight of the putter is located adjacent to
that area which minimizes the resultant torque effect often present
during a putting stroke. In fact, it is even more effective if the
actual "sweet spot" 30 is located on the vertical axis of the shank
and shaft in alignment therewith. With the majority of the weight
of the head located in area 29, when the ball is struck with any
portion of head 23 in that particular area, there is very little
turning or torque effect on the shaft of the club. Therefore, there
is little danger of turning of the head during the follow through
in the putting stroke and consequently little danger of the ball
being misdirected in its path of travel. Additionally, if the ball
is struck at either tip end 33 or 34 of the hitting face 25, since
the majority of the weight is centrally located on head 23, there
will be only a small turning moment since the turning moment is
dependent upon the amount of weight and its distance from the
center of rotation which is along the vertical axis previously
discussed. Therefore, there is little danger that the club will be
turned in one's hands with a normal grip even if the ball is struck
at the extremities of hitting surface 25. The club head will tend
to retain its direction of travel and complete the proper stroke
direction imparting the proper path of travel to the ball being
struck. By concentrating approximately at least half of the weight
in the head 23 proximal to the axis of the shank and the extension
of that axis, the danger of turning of the shaft in one's hand is
greatly alleviated. In fact, if the "sweet spot" or hitting center
of the head is positioned on the above-mentioned axis, there is
virtually no turning movement present and the ball will be struck
true and straight.
By having head 23 in the shape of a foot with the instep portion
being formed by recess 27 and the end portions 33 and 34 having a
curved undersurface the point of contact between the bottom of head
23 and the ground is minimized. In fact, it will only contact the
ground at points 31 and 32 on its undersurface. The area of contact
is naturally dependent upon the angle of curvature at that point.
In this manner, the danger of stubbing the club head is alleviated
since there are only two points of contact and the remainder of the
golf club is spaced from the ground.
Furthermore, by shaping head 23 so that a projecting portion 28 is
substantially vertically aligned with recess 27 and proximal to the
axis of shank 22 and its extension, the center of mass of this
portion of the head is raised from the ground a significant amount.
This naturally raises the point of contact between the head 23 and
the ball since the "sweet spot" or hitting center is generally
proximal to the center of mass of the head. Therefore, by removing
a portion of the weight of the head by forming recess 27 and
providing additional material as projection 28, the center of this
mass area is represented by point 30 on the head which is at a
higher horizontal point with respect to the ground than the central
horizontal axis of the hitting surface 25 of blade 23 including end
portions 33 and 34.
By raising the point of contact 30 on the hitting surface, it
achieves the effect of striking the ball above its centerline and
imparting overspin to the ball which, as discussed above, is
extremely desirable in putting since the overspin will tend to roll
the ball into the hole when the ball comes in contact with any
portion of the hole.
Furthermore, by having a higher hitting position on hitting surface
25, when the ball is lying in the fringe area around the green, the
ball will be struck more positively with a normal stroke of the
club since the head will rest down in the grass contacting the
ground on points 31 and 32. At this position, the point of contact
which is ideally point 30 will still be relatively centrally
located with respect to the ball and will facilitate the provision
of a positive stroke of the ball by the club 20. Naturally it
should be kept in mind that the presence of this higher hitting
center on hitting face 25 also minimizes the danger of stubbing the
putter blade in the fringe area which is considerably rougher in
terrain than the actual green itself.
By achieving this more positive hitting action with the structure
of head 23 as described in this invention, there is no necessity to
grip the club too tightly to compensate for the torque effect which
causes the golfer to lose the proper feel between the golf club and
the ball during the stroking action. Furthermore, there is no
danger that the torque effect will adversely affect the putting
stroke if the club is gripped too loosely due to the minimization
of that effect by the structure of the club. In this manner, the
above-discussed problems of putting are alleviated by the putter
described herein.
An additional feature which is readily apparent from the structure
of the putter as shown in FIGS. 1-3 is the fact that two identical
hitting faces 25 and 26 in opposed and parallel relationship are
present on head 23 so that putter 20 may be utilized in both a
right-hand a left-hand manner for striking the ball. This naturally
makes the putter available for both right-handed and left-handed
golfers as well as permitting a right-handed golfer to use the
putter in a reverse manner should his ball be located in a position
which would make a normal right-handed stroke virtually
impossible.
An additional advantage of the structure of the putter of this
invention is the provision of the short rear end portion 34 on the
hitting surface whereby the majority of weight at this end of the
putter is in the portion proximal to the axis extending through
shank 22 and vertically downward through head 23. With this
structure, by striking the ball in the area between the vertical
axis and rear end portion 34, it has been found that a force will
be imparted to the golf ball so that it will tend to retain its
line of travel even when positioned on the green in what is known
as a side hill line. Normally, the tendency of the ball in this
position is to tend to curve to the downhill side of the hole when
struck by the putter. However, when struck with the putter of this
invention in the manner just described, the putt will tend to
retain its direct line of travel to the hole due to the spin
imparted to the ball thereby minimizing the amount of curve of the
ball downhill below the hole. Therefore, by utilizing the putter in
this manner, the golfer need not compensate as greatly for the
normal break or roll of the green and can hit the ball more
directly toward the hole itself which is a considerable advantage
in the art of putting.
Thus the aforementioned objects and advantages are most effectively
attained. Although one preferred embodiment of this invention has
been disclosed in detail herein, it should be understood that this
invention is in no sense limited thereby; and its scope is to be
determined by that of the appended claims.
* * * * *